Consolidated Statements of Comprehensive Income - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
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| Statement of Comprehensive Income [Abstract] | ||
| Net income (loss) | $ 522 | $ 405 |
| Other comprehensive income (loss), net of tax: | ||
| Net unrealized gains (losses) on securities available for sale, net of income taxes of $55 and $(136) | (172) | 424 |
| Net unrealized gains (losses) on derivative financial instruments, net of income taxes of $29 and $(62) | (91) | 193 |
| Net pension and postretirement benefit costs, net of income taxes of $(1) and $(21) | 2 | 66 |
| Total other comprehensive income (loss), net of tax | (261) | 683 |
| Comprehensive income (loss) attributable to Key | $ 261 | $ 1,088 |
| X | ||||||||||
- Definition Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount, after tax and reclassification adjustment, of gain (loss) in value of unsold investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), attributable to parent. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount, after tax and reclassification adjustment, of (increase) decrease in accumulated other comprehensive income for defined benefit plan, attributable to parent. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Amount, after tax and adjustments, of gain (loss) from increase (decrease) in value of excluded component of derivative designated and qualifying as hedge, attributable to parent. Adjustments include, but are not limited to, reclassifications for sale and settlement, and amounts recognized under systematic and rational method. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount after tax of other comprehensive income (loss) attributable to parent entity. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- References No definition available.
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- References No definition available.
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